The present invention relates to an ink jet print head and a manufacturing method thereof.
In an ink jet printer, as described in Japanese Patent Application Laid-Open Nos. 2004-25636 and 2005-246779, a cavity unit comprising nozzles arranged in lines and pressure chambers for the respective nozzles is joined with a plate-type piezoelectric actuator having energy generating units formed for the pressure chambers and a flexible flat cable is further joined with the rear face thereof so as to form a record head. An ink jet print head is formed by bonding and fixing the record head at a reinforcing frame and mounting the assembly in a head holder having substantially the shape of a box as described in Japanese Patent Application Laid-Open No. 2005-246779, The ink jet print head is constructed to apply pressure for causing the pressure chambers to discharge ink by selectively driving the energy generating units of the actuator so that ink is discharged from the nozzles. A cover plate (a protective cover in Japanese Patent Application Laid-Open No. 2005-246779) is attached to the nozzle face of the record head of the ink jet print head surrounding the cavity unit so as to correct a step between the cavity unit and the reinforcing frame and slightly protrudes downward from the nozzle face so that the nozzles and the nozzle face is kept from being damaged by contact with recording paper during scanning of the head holder.
The cavity unit is constructed by laminating and bonding a plurality of plates sequentially and disposing a nozzle plate having nozzles provided at the bottom layer. Since nozzles which directly jet ink have a direct influence on the quality of ink jet, a high accuracy of machining of the hole size or the nozzle position is required at the time of nozzle machining. Accordingly, a method described in Japanese Patent Application Laid-Open No. 2005-246779 has been employed. A nozzle plate can be machined with a high accuracy of the position and the hole size of the nozzles when a nozzle unit is prepared by bonding a first plate (a nozzle plate in Japanese Patent Application Laid-Open No. 2005-246779), which is to be a nozzle plate, with a second plate (a first spacer plate in Japanese Patent Application Laid-Open No. 2005-246779), which has an opening, at a position corresponding to each nozzle and laser is radiated from the second plate side to the opening. The other plates are then laminated and bonded sequentially on the nozzle unit and an actuator is further laminated and bonded on the top thereof.